Battery grid continuous casting shoe and machine

Abstract

A shoe for dispensing molten lead into a mold cavity of rotating drum to continuously cast a web of a plurality of serially connected grids for lead acid batteries. The shoe may have an elongate orifice slot in a face confronting the drum, a molten lead supply slot opening into an upper recessed portion of the orifice slot and an excess molten lead return slot communicating with the recessed portion downstream of the supply slot.

The invention claimed is: 
     
       1. For a battery grid continuous casting machine with a rotary drum with a mold cavity therein, a casting shoe comprising:
 a body with a face configured to confront the rotary drum and extending generally axially over at least an axial extent of the mold cavity of the rotary drum; 
 a longitudinally elongate orifice slot in the body and opening into the confronting face of the body and extending longitudinally across the axial extent of the mold cavity; 
 a longitudinally elongate molten lead supply slot opening into the orifice slot along at least substantially a longitudinal extent of the orifice slot and upstream of the orifice slot of the confronting face relative to the direction of flow of molten lead through the supply slot and into the orifice slot; 
 a molten lead supply passage in the body and communicating with the supply slot upstream of the orifice slot and at least substantially throughout a longitudinal extent of the supply slot; 
 a longitudinally elongate excess molten lead return slot separate from the supply slot and opening into the orifice slot downstream of the supply slot and extending along at least substantially the longitudinal extent of the orifice slot; and 
 a return passage in the body separate from the supply passage and the supply slot, the return passage communicating with the return slot downstream of the orifice slot and at least substantially throughout a longitudinal length of the return slot, the return passage having a molten lead inlet adjacent one of its ends, a molten lead outlet adjacent the other of its ends, and being configured to receive excess molten lead from the return slot downstream of the orifice slot and to discharge such excess molten lead from the return slot through the outlet of the return passage. 
 
     
     
       2. The casting shoe of  claim 1 , wherein the supply slot is inclined downwardly relative to a direction of rotation of the rotary drum past the orifice slot at an acute angle relative to an imaginary radius of the rotary drum extending through a center of the generally circumferential width of the opening of the orifice slot into the confronting face. 
     
     
       3. The casting shoe of  claim 2 , wherein the acute angle of the supply slot is in the range of 50°-70°. 
     
     
       4. The casting shoe of  claim 2 , wherein the return slot from the orifice slot is inclined downwardly relative to the direction of rotation of the rotary drum past the orifice slot and away from the orifice slot at an acute angle relative to an imaginary radius of the rotary drum extending through the center of the generally circumferential width of the opening of the orifice slot into the confronting face. 
     
     
       5. The casting shoe of  claim 1 , wherein the opening of the return slot from the orifice slot is inclined downwardly relative to the direction of rotation of the rotary drum past the orifice slot and away from the orifice slot at an acute angle relative to an imaginary radius of the rotary drum extending through a center of the generally circumferential width of the opening of the orifice slot into the confronting face. 
     
     
       6. The casting shoe of  claim 5 , wherein the acute angle of the return slot is in the range of about 20°-30°. 
     
     
       7. The casting shoe of  claim 1 , wherein the supply passage has an inlet adjacent one of its ends and an outlet adjacent the other of its ends. 
     
     
       8. The casting shoe of  claim 7 , wherein the supply passage extends generally axially through the body and is configured to receive molten lead at a super atmospheric pressure through its inlet and to discharge through its outlet excess molten lead not supplied through the supply passage to the orifice slot. 
     
     
       9. The casting shoe of  claim 7 , which also comprises the body having axially spaced apart ends, and the outlet of the supply passage and the outlet of the return passage are both adjacent the same one of the ends of the body. 
     
     
       10. The casting shoe of  claim 9 , which also comprises an axially elongate molten lead return supply tube received in the return passage and having an outside diameter smaller than an inside diameter of the return passage and a nozzle adjacent the molten lead outlet of the return passage. 
     
     
       11. The casting shoe of  claim 7 , which also comprises an isolation slot through the body and disposed generally radially outward of the supply passage. 
     
     
       12. The casting shoe of  claim 1 , which also comprises the body having axially spaced apart ends, and an inlet of the supply passage and the inlet of the return passage are both adjacent the same one of the ends of the body. 
     
     
       13. The casting shoe of  claim 12 , wherein the return passage is configured to receive a supply of molten lead through its inlet and to discharge such molten lead and excess molten lead from the return slot through the outlet of the return passage. 
     
     
       14. The casting shoe of  claim 13 , which also comprises an axially elongate molten lead return supply tube received in the return passage and having an outside diameter smaller than an inside diameter of the return passage and a nozzle adjacent the molten lead outlet of the return passage. 
     
     
       15. The casting shoe of  claim 12 , which also comprises an axially elongate molten lead return supply tube received in the return passage and having an outside diameter smaller than an inside diameter of the return passage and a nozzle adjacent the molten lead outlet of the return passage. 
     
     
       16. The casting shoe of  claim 15 , wherein the molten lead return supply tube also has a plurality of spaced apart outlet passages through a side wall of the tube through which molten lead may be discharged into the return passage. 
     
     
       17. The casting shoe of  claim 12 , which also comprises an isolation slot through the body and disposed generally radially outward of the return passage. 
     
     
       18. The casting shoe of  claim 1 , wherein the ratio of a minimum cross-sectional flow area of the orifice slot through the confronting face to a minimum cross-sectional flow area of the supply slot into the orifice slot is in the range of 8:1 to 15:1. 
     
     
       19. The casting shoe of  claim 18 , wherein a minimum cross-sectional flow area of the return slot to a minimum cross-sectional flow area of the supply slot to the is in the range of 5:1 to 10:1. 
     
     
       20. The casting shoe of  claim 1 , wherein the ratio of a minimum cross-sectional flow area of the orifice slot through the confronting face to a minimum cross-sectional flow area of the supply slot into the orifice is in the range of 9:1 to 11:1. 
     
     
       21. The casting shoe of  claim 1 , wherein the ratio of a minimum cross-sectional flow area of the orifice slot opening into the confronting face to a minimum cross-sectional flow area of the return slot is in the range of 1:1 to 3:1. 
     
     
       22. The casting shoe of  claim 1 , wherein the ratio of a minimum cross-sectional flow area of the orifice slot opening into the confronting face to a minimum cross-sectional flow area of the return slot is in the range of 1:1 to 2:1. 
     
     
       23. The casting shoe of  claim 1 , wherein a minimum cross-sectional flow area of the return slot to a minimum cross-sectional flow area of the supply slot is in the range of 5:1 to 10:1. 
     
     
       24. The casting shoe of  claim 1 , wherein a minimum cross-sectional flow area of the return slot to a minimum cross-sectional flow area of the supply slot is in the range of 6:1 to 9:1. 
     
     
       25. The casting shoe of  claim 1 , further comprising a plurality of axially spaced apart ribs projecting radially outwardly from the face of the body.